In the 70s, I had a pair of ornates that would not spawn. So I read up on influencing spawns and decided to try injecting each poly with 1.0cc of PMSG. I found a farm that had what I needed. I followed a horse around, while carrying a bucket, until she had to pee. When she started, I had to hurry to her without spooking her, and get the bucket underneath her to catch the sample I needed. The elbow gloves and vet's apron did nothing to keep me dry. Then, of course, I had to get the bucket back to school without upsetting it too much in the back of my car.
See, PMSG is 'Pregnant Mare Serum Gonadotropin'. I needed it to stimulate the ornates to spawn. It's what had to be done before the commercially-available Ovi-Prim.